Spraying device



June 16, 1925. 1,541,794

A. COSTA SPRAYING DEVICE Filed March 17, 1923 INVENTOR f BY W. M, Wm

M ATTORNEYS Patented June 16, 1925. I

UNITED STATES ARMANDO COSTA, OF GREAT KILLS, NEW YORK.

SPRAYING DEVICE.

Application filed. March 17, 1923. Serial No. 625,685.

To all whom it may concern:

Be it known that I, ARMANDO Cos'rA, a citizen of the United States, residing at 35 David Street, Great Kills, Staten Island, in the county of Richmond, State of New York, have invented certain new and useful Iniprovements in Spraying Devices; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains, to make and use the, same.

This invention relates tospraying devices, particularly devices of the character which are known in the trade as air brushes, for the application of paints, varnishes. etc.

Air brushes of this general character have been on the market for many years, and consist essentially of an attachment for the paint receptacle with a delivery pipe projecting into the receptacle and with its nozzle arranged adjacent the air nozzle in such manner-that the force of the air current blowing across thepaint nozzle willdraw the paint outof its receptacle and spray it on to the surface to be covered. The air passages are supplied with suitable regulating and cut-off valves whereby the spray may be regulated to suit the particular conditions of the work under way.

The object of the present invention is to produce a device of this character having a minimum number of working parts and which is designed to require little attention in operation and not to be afiected by wear resulting from prolonged use of the apparatus.

A further object of the invention is to provide a device of this character which consists preferably of a single casting having a few passages bored therein and with no parts requiring accurate fitting or machining, whereby the device is of superior strength and capable of withstanding the rough usage to which such apparatus is put, and at the same time is of very low manufacturing cost.

In the accompanying drawing I have shown a preferred embodiment of my improved air brush, and in the said drawings:

Figure 1 shows the brush in vertical section; and

Fig. 2 shows the brush in elevation and attached to a source of air under pressure.

Referring to the drawings, particularly to Fig. 1, 1 indicates the casting or body piece of the air brush which is of the shape shown, its lower part forming a base plate 2 to which the cover 3 for the paint receptacle 4 is attached by brazing or otherwise. The cover and neck of the paint can are preferably threaded to permit ready removal of the can for re-filling, and projecting through the base plate is a pipe or tube 5 of a length to extend close to the bottom of the paint receptacle, the upper-end of the tube being provided with a paint nozzle 6 threaded on the paint tube for adjustment up and down so as to bring the nozzle more or less into the air stream, whereby the ejector effect of the air current is regulated.

At the end of the base plate 2 away from the tube 5 the casting 1 is formed with a solid portion in which the air passages containing the regulating valves are bored. Also, the casting is preferably provided with an extension 7 through which the air passage 8 is bored, the extension also being shaped to receive the grip 9 by which the painter holds the brush and directs the spray over the surface to which it is to be applied.

The air passage 8 connects with a horizontal valve chamber 10 in the solid part of the casing, which chamber contains a ball valve 11 held against its seat by a spring 12 whose outer end is seated in the regulating cap 13 which closes the outer end of the chamber 10. At the inner end the chamber 10 is provided with an extension 14 of reduced diameter, thereby forming a shoulder against which the valve ball 11 seats to cut ofi the passage of air from the chamber 10 into the extension 14. ,The chamber 10 and the extension 14 are formed in the casting 'by drilling and counterboring, and also formed in the casting in a smilar manner is a vertical passage 15 which opens into the extension 14 beyond the valve seat.

The casting 1 is provided with an upper tubular part 16 extending parallel to the plate 2 and forming a horizontal passage whose end terminates near the paint nozzle 6, the tubular part 16 being also provided with a nozzle piece whereby the air under pressure will be properly directed across the paint nozzle. The tubular part 16 is counterbored at the end to receive a regulating valve 17 whereby the pressure of the air may be properly controlled.

Working in the extension 14 is a plunger 18 whose inner end is shaped to fit against the valve ball while its outer end projects through and is guided in a. hole bored in the body 1 and working against the projecting stem of the plunger 18 is a lever or trigger 19 hinged to the casting in the manner shown, and depending to a position to be engaged by the finger of the painters hand when holding the grip 9.

The upper end of the vertical bore 15 is preferably closed with a hook 20 whereby the brush may be -hung to the painters belt or otherwise, when not in use, and the lower end of the tube 8 is provided with the usual hose connection 21 for attachment of the device to a suitable source of air pressure, as shown in Fig. 2.

The operation of the device will be readily understood from the above description. The trigger 19 serves to open the ball valve 11 when the brush is to be used, allowing the air under pressure to pass through the regulating valve 17 into the upper passage and through the air nozzle across the paint nozzle to effect the spraying of the paint in the usual manner. The ball valve is particularly desirable and useful in this connection, for the reason that it soon grinds its own seat on the shoulder between the two passages, and it may be effectively operated by a plunger entirely separate from the ball. Where check valves of ordinary design are used in this connection it has been found that the valves are liable to be canted by the pressure on the trigger and unless the valve surfaces are repeatedly ground, soon wear so that they no longer hold the air The Workin of the ball valve by the trigger has the efiect of changing the engaging surface of the ball from time to time so that it wears evenly and smoothly and maintains a tight joint without grinding or attention. The arrangement of the regulating valve in the manner shown is also of importance. These valves are necessarily small, as but a fine air stream is required for effecting the spray. By the arrangement shown the stem of the valve is closely adjacent the body part of the casting where it is protected from damage and from the rough handling to which such devices are subjected.

I claim:

In an apparatus of the class described, the combination of a main casting, a connection at one end of said casting for a paint receptacle, a valve block at the other end of said casting, a valve chamber bored in said casting, said valve chamber having an extension of lesser diameter than the valve chamber, forming a valve seat therein, a

valve Working in said chamber against said seat, plunger for said valve in said extension, an air passage bored in said casting adjacent said valve chamber, a communicating bore in said casting extending across said passage into the extension of said valve chamber, and a regulating valve in said passage, saidvalve extending across said bore.

In testimony whereof I affix my signature.

ARMANDO COSTA. 

